MedArray has successfully developed under SBIR Phase I and II, a novel silicone membrane hollow fiber for use in blood oxygenators. Our patented silicone hollow fiber has great commercial potential for use in long term extracorporeal membrane oxygenation (ECMO) as well as routine cardiopulmonary bypass. Because ECMO can last more than 1 day, dense rather than microporous membranes are typically used to prevent plasma leakage. The membrane of choice for ECMO is silicone because of its excellent blood compatibility, and because it has no pores for plasma leakage. In the US, the only oxygenator currently FDA approved for use in long term applications is Medtronic's ECMO oxygenator. However, this spiral wound, flat sheet silicone oxygenator's design dates back to 1963, and has many disadvantages including areas of blood stagnation, minimal convective mixing, large blood contact surface areas, and high hemodynamic resistance. The lack of a suitable dense membrane hollow fiber for long term use in the US has prevented US manufacturers from developing a more efficient hollow fiber based long term oxygenator. Our studies in Phase I and II have shown that our silicone hollow fibers'performance is superior to the spiral wound silicone membranes, and comparable to microporous membranes in gas transfer and platelet trends. However, our silicone membrane cannot leak plasma or grossly embolize gas into the blood side like microporous membranes. Moreover, we have shown in an 11-day in-vivo study that our membrane can perform and sustain the rigors of long- term cardiorespiratory support. MedArray's silicone membrane hollow fiber will enable a strong ECMO oxygenator market contender in the US and abroad. This proposal is aimed at continuing the development of our proprietary dense membrane hollow fiber while focusing on all aspects relevant to implementing our membrane in clinical oxygenators. Specifically, we will investigate the effects of membrane materials on safety, effectiveness, and biocompatibility following FDA guidelines to ultimately meet their requirements and expectations prior to clinical use. We will also rigorously test our membrane in oxygenators for gas transfers performance, and thrombogenicity in long-term in-vivo studies. Finally, we will continue refining our membrane fabrication processes by assessing the parameters pertinent to quality control and cost reduction to ultimately establish a robust and controlled process compliant with good manufacturing practices (GMP).This research and development work will result in a membrane for long-term blood-gas transfer that can replace current membrane technology dating back to 1963. The proposed membrane will enable the manufacture of highly efficient blood oxygenators with superior gas transfer, and reduced risk of deadly complications compared to currently used long term membranes.